Sulphuric acid animal hazards 

There is concern over the heavy use of sulphuric acid and the impact this has on wild and domestic animals in the UK. 

Some three to four times more sulphuric acid, by weight, is used in the UK than the next most used pesticide (currently chlormequat)¹. The UK is believed to be the only country in Europe still using the substance². It was described as a ‘British tradition’ by agrochemical industry representatives recently³. 
    Sulphuric acid is used at 77% strength on potato haulms at the end of the growing period to destroy the green tops. The chemical is sold in tanks, and used at 800 litres/ha between 1 May and 15 November. It is also used to achieve ‘skin-set’ which allows farmers to leave the potatoes in the ground for around two weeks before the crop is lifted. This achieves the consistent size required by supermarket buyers, reduces the need for above-ground storage facilities, and allows the farmer to fit in with the ‘just-in-time’ management practices of the supermarkets. 
    The National Association of Agricultural Contractors promote a Code of Practice⁴ and a new register of sulphuric acid contractors, in an attempt to reassure buyers and the public that it is possible to use the chemical safely. Risks to operators and the public, especially to people living next to potato fields, are high, and the controls inadequate. The Health & Safety Executive are investigating fears that sulphuric acid mist, as an acute irritant, may pre-dispose operators to laryngeal cancer⁵. PAN UK receives numerous complaints about sulphuric acid, especially at the start of the use period in May.
    The use of sulphuric acid creates problems for animals. Any animal, wild or domestic, which comes into contact with the chemical suffers severe burns. The UK National Farmers’ Union does not acknowledge the effects on animals claiming that animals hiding beneath the potato haulms (foliage) are protected against the spray. However, PEX contact Stephen Duncan, whose own exposure to sulphuric acid resulted in burning skin sensations, respiratory problems and general poisoning symptoms⁶ says that this is impossible as the haulms are totally destroyed by the acid. The issue of sulphuric acid use is also being considered by the UK Royal Society for the Prevention of Cruelty to Animals (RSPCA) following contact with PEX. Alternatives are available: mechanical haulm-removal with natural skin-set takes around three weeks, rather than two. 
    Please contact your local supermarket to demand that non-chemical alternatives to sulphuric acid be used in the production of their potatoes. (AC)

1. Dr Miles Thomas, Central Science Laboratory Pesticide Usage Survey Group, email 24 October 2003.
2. Pers Comm,. Guenter Lach, Dr Specht and Partner, Chemishc Laboratorien GmbH, Germany, at Pesticide residues in baby food: scientific challenges to the industry, Association of Applied Biologists, Rothamsted, 17 October 2003.
3. At the Pesticide residues in baby food conference (see ref 2).
4. www.naac.co.uk/Codes/acidcode.asp
5. Health and Safety Executive, http://213.212.77.20/pubns/chan25.htm
6. PEX Newsletter 20, Personal EXchange.

[This article first appeared in Pesticides News No. 62, December 2003, page 21]